In prior art, impellers ore used for a variety of applications. For example, impellers may be used as a rotating component in pumps as, e.g., centrifugal pumps, for transferring energy from a motor that drives the pump to a fluid being pumped. Usually, impellers are made from metal and are configured as short cylinders with an inlet for incoming fluid, vanes for pushing the fluid radially, and a bore to accept a drive shaft.
Small impellers nowadays are made from plastic material by injection molding. Impellers made of metal can be produced by casting or by welding metal sheets. Both methods are expensive.
An effective and economic process known from prior art to shape parts and components in a single operation and in a high volume is the so called metal injection molding (MIM) process according to which powdered metal is mixed with a binder material so that a feedstock is obtained which may be handled by plastic processing equipment by means of injection molding.
However, a problem with respect to the above described metal injection molding process is that complex three dimensional geometries may not be implemented.